Camera cranes are often used in motion picture and television production. A motion picture or television camera is typically mounted on a crane arm, which is supported on a mobile base, dolly, or truck. The mobile base may be pushed and steered by hand. Larger units, which have more weight-carrying capacity, and longer reaches, typically have electric driving motors powered by onboard batteries. Some mobile bases also include conventional gasoline or diesel engines, and may serve as over-the-road vehicles.
Telescoping camera cranes have a telescoping arm that can extend and retract. This allows for a broader range of camera movement. These types of cranes use various electrical systems. Consequently, these cranes tend to have performance problems if used in rain or wet conditions and cannot be used underwater. A newer telescoping camera crane design uses a hydraulic system including a pair of hydraulic cylinders which alternately pull on cables to extend and retract telescoping crane sections. This system is efficient and virtually waterproof. It also provides smooth and near silent extension and retraction movement. In its simplest form, this crane design may have a single telescoping crane section. To provide a longer reach, multiple telescoping sections may be used, along with multiple sets of cables for extending and retracting the telescoping sections. The cables that are driven directly by the hydraulic or other actuating system, referred to here as primary cables, carry the highest tensile loads in the camera crane. These primary cables accordingly may tend to stretch momentarily when the actuating system initially pulls on the cables. This can result in a slight initial delay of the extending or retracting telescoping camera crane arm movement. In many cases, this delay has no significant effect, for example with slow arm movements. However, for other camera movements, a delay of even a fraction of a second can make precise crane arm movements more difficult to achieve. The delay can also adversely affect sensory aspects of crane arm operation.